Acute High Fat Diet Consumption Activates the Mesolimbic Circuit and Requires Orexin Signaling in a Mouse Model

Overconsumption of palatable energy-dense foods has negative health implications and it is associated with obesity andseveral eating disorders. Currently, little is known about the neuronal circuitries activated by the acute ingestion of arewarding stimulus. Here, we used a combination of immunohistochemistry, pharmacology and neuronal tracing analysesto examine the role of the mesolimbic system in general, and the orexin neurons in particular, in a simple experimental testin which naı ̈ve mice are allowed to spontaneously eat a pellet of a high fat diet (HFD) for 2 h. We found that acute HFDactivates c-Fos expression in several reward-related brain areas, including the ventral tegmental area (VTA), nucleusaccumbens, central amygdala and lateral hypothalamic area. We also found that: i- HFD-mediated orosensory stimulationwas required for the mesolimbic pathway activation, ii- acute HFD differentially activates dopamine neurons of theparanigral, parabrachial pigmented and interfascicular sub-regions of the VTA, and iii- orexin neurons of the lateralhypothalamic area are responsive to acute HFD. Moreover, orexin signaling blockade, with the orexin 1 receptor antagonistSB-334867, reduces acute HFD consumption and c-Fos induction in the VTA but not in the other mesolimbic nuclei understudy. Finally, we found that most orexin neurons responsive to acute HFD innervate the VTA. Our results show that acuteHFD consumption recruits the mesolimbic system and that the full manifestation of this eating behavior requires theactivation of orexin signaling.Fil: Valdivia Torres, Lesly Spring. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Patrone, Anabela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Reynaldo, Mirta Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Perello, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentin

Considerations about rodent models of binge eating episodes

A binge eating episode is defined as an uncontrolled event of hyperphagia, in which people quickly eat a large amount of food while feeling a sense of loss of control over eating (Wolfe et al., 2009). Binge eating episodes are observed in a variety of human disorders including bulimia nervosa (BN), binge eating disorder (BED), and the binge/purge subtype of anorexia nervosa (AN) (Berger and Tanofsky-Kraff, 2012). Binge eating episodes are also present in overweight and obese people, as well as non-clinical populations under specific circumstances such as stress. The etiology of this behavior is currently unknown. The use of rodent models has been essential for understanding the pathogenesis of many human diseases; however, it is challenging to mimic all features of human binge eating in rodent models (Corwin and Buda-Levin, 2004; Perello et al., 2010a). In particular, these models should not only display the objective characteristics of a binge eating episode, namely the consumption of a large amount of food in a short period of time, but also the subjective characteristics of the feeling of loss of control. Recently, we examined the neuronal circuitries activated in naïve mice allowed to spontaneously eat a high fat diet (HFD) pellet for 2 h (Valdivia et al., 2014). We found that satiated mice with free access to regular chow rapidly consume a significant amount of HFD when exposed to it, and that HFD intake recruits centers of the mesolimbic pathway, which are known to be activated in human beings displaying binge eating behavior (see below). Experts in the field agreed that our simple model of HFD overconsumption could be relevant for studying neuronal aspects of binge eating behaviors. However, some reviewers argued that it was misleading to describe our model as a model of binge eating. Some criticisms were that our model lacked indications of feelings of loss of control, repeated feeding episodes, escalation of intake over time, a significant level of hyperphagia, and evidence that bingeing occurred in the face of aversive consequences. The notable divergence in the opinion of the journal´s reviewers made evident that a comprehensive debate about rodent binge eating models is needed. Here, we briefly present our opinion about the features that a rodent model should fulfill in order to be considered a reasonable model of binge eating episodes and its implications in terms of the neuronal circuits involved.Fil: Perello, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Valdivia Torres, Lesly Spring. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Garcia Romero, Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Raingo, Jesica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentin

La gamificación como motivación para el aprendizaje del curso de programación en estudiantes de un instituto de educación superior de la región Arequipa

El presente documento consiste en una propuesta de innovación para atender el problema de baja motivación en el aprendizaje del curso de programación, que presentan los alumnos del V ciclo de la carrera de computación de un instituto de la región Arequipa. Los contenidos de los cursos de programación no son sencillos y se caracterizan por requerir habilidades de abstracción, resolución lógica de problemas, e identificación y resolución de errores para poder asimilarlos, por lo que se requiere mantener la motivación del alumno para lograr el aprendizaje. La propuesta tiene como objetivo mejorar la motivación hacia el aprendizaje del curso de programación teniendo como recurso la gamificación para incorporar la resolución de problemas en su metodología y para generar la auto-reflexión de los alumnos sobre la evaluación de su desempeño y rendimiento en el curso. Las estrategias y actividades utilizadas para lograr este objetivo se organizaron en fases del ciclo de vida de una propuesta. En la fase de planificación se analizó el sílabo del curso y se diseñó la experiencia gamificada identificando los elementos que mejor se adecuen a los contenidos y características del curso, en la fase de implementación se configuró el LMS Moodle para dar soporte al curso gamificado, en la fase de ejecución se utilizaron instrumentos en la recolección de datos para realizar informes parciales, y en la fase de evaluación se analizaron los informes parciales y se elaboró el informe final. Los resultados de la experiencia piloto arrojaron que la aplicación de gamificación en el curso sí mejoró la motivación hacia el aprendizaje del curso de programación, aunque ésta no haya sido suficiente para mejorar el rendimiento de la mayoría de los alumnos.Tesi

Acute High Fat Diet Consumption Activates the Mesolimbic Circuit and Requires Orexin Signaling in a Mouse Model

Overconsumption of palatable energy-dense foods has negative health implications and it is associated with obesity andseveral eating disorders. Currently, little is known about the neuronal circuitries activated by the acute ingestion of arewarding stimulus. Here, we used a combination of immunohistochemistry, pharmacology and neuronal tracing analysesto examine the role of the mesolimbic system in general, and the orexin neurons in particular, in a simple experimental testin which naı ̈ve mice are allowed to spontaneously eat a pellet of a high fat diet (HFD) for 2 h. We found that acute HFDactivates c-Fos expression in several reward-related brain areas, including the ventral tegmental area (VTA), nucleusaccumbens, central amygdala and lateral hypothalamic area. We also found that: i- HFD-mediated orosensory stimulationwas required for the mesolimbic pathway activation, ii- acute HFD differentially activates dopamine neurons of theparanigral, parabrachial pigmented and interfascicular sub-regions of the VTA, and iii- orexin neurons of the lateralhypothalamic area are responsive to acute HFD. Moreover, orexin signaling blockade, with the orexin 1 receptor antagonistSB-334867, reduces acute HFD consumption and c-Fos induction in the VTA but not in the other mesolimbic nuclei understudy. Finally, we found that most orexin neurons responsive to acute HFD innervate the VTA. Our results show that acuteHFD consumption recruits the mesolimbic system and that the full manifestation of this eating behavior requires theactivation of orexin signaling.Facultad de Ciencias ExactasInstituto Multidisciplinario de Biología Celula

Considerations about rodent models of binge eating episodes

A binge eating episode is defined as an uncontrolled event of hyperphagia, in which people quickly eat a large amount of food while feeling a sense of loss of control over eating (Wolfe et al., 2009). Binge eating episodes are observed in a variety of human disorders including bulimia nervosa (BN), binge eating disorder (BED), and the binge/purge subtype of anorexia nervosa (AN) (Berger and Tanofsky-Kraff, 2012). Binge eating episodes are also present in overweight and obese people, as well as non-clinical populations under specific circumstances such as stress. The etiology of this behavior is currently unknown. The use of rodent models has been essential for understanding the pathogenesis of many human diseases; however, it is challenging to mimic all features of human binge eating in rodent models (Corwin and Buda-Levin, 2004; Perello et al., 2010a). In particular, these models should not only display the objective characteristics of a binge eating episode, namely the consumption of a large amount of food in a short period of time, but also the subjective characteristics of the feeling of loss of control. Recently, we examined the neuronal circuitries activated in naïve mice allowed to spontaneously eat a high fat diet (HFD) pellet for 2 h (Valdivia et al., 2014). We found that satiated mice with free access to regular chow rapidly consume a significant amount of HFD when exposed to it, and that HFD intake recruits centers of the mesolimbic pathway, which are known to be activated in human beings displaying binge eating behavior (see below). Experts in the field agreed that our simple model of HFD overconsumption could be relevant for studying neuronal aspects of binge eating behaviors. However, some reviewers argued that it was misleading to describe our model as a model of binge eating. Some criticisms were that our model lacked indications of feelings of loss of control, repeated feeding episodes, escalation of intake over time, a significant level of hyperphagia, and evidence that bingeing occurred in the face of aversive consequences. The notable divergence in the opinion of the journal´s reviewers made evident that a comprehensive debate about rodent binge eating models is needed. Here, we briefly present our opinion about the features that a rodent model should fulfill in order to be considered a reasonable model of binge eating episodes and its implications in terms of the neuronal circuits involved.Instituto Multidisciplinario de Biología Celula

Escalation in high fat intake in a binge eating model differentially engages dopamine neurons of the ventral tegmental area and requires ghrelin signaling

Binge eating is a behavior observed in a variety of human eating disorders. Ad libitum fed rodents daily and time-limited exposed to a high-fat diet (HFD) display robust binge eating events that gradually escalate over the initial accesses. Intake escalation is proposed to be part of the transition from a controlled to a compulsive or loss of control behavior. Here, we used a combination of behavioral and neuroanatomical studies in mice daily and time-limited exposed to HFD to determine the neuronal brain targets that are activated – as indicated by the marker of cellular activation c-Fos – under these circumstances. Also, we used pharmacologically or genetically manipulated mice to study the role of orexin or ghrelin signaling, respectively, in the modulation of this behavior. We found that four daily and time-limited accesses to HFD induce: (i) a robust hyperphagia with an escalating profile, (ii) an activation of different sub-populations of the ventral tegmental area dopamine neurons and accumbens neurons that is, in general, more pronounced than the activation observed after a single HFD consumption event, and (iii) an activation of the hypothalamic orexin neurons, although orexin signaling blockage fails to affect escalation of HFD intake. In addition, we found that ghrelin receptor-deficient mice fail to both escalate the HFD consumption over the successive days of exposure and fully induce activation of the mesolimbic pathway in response to HFD consumption. Current data suggest that the escalation in high fat intake during repeated accesses differentially engages dopamine neurons of the ventral tegmental area and requires ghrelin signaling

A well preserved skeleton of the fossil shark Cosmopolitodus hastalis from the late Miocene of Peru, featuring fish remains as fossilized stomach contents

Both the preservation of the poorly mineralized skeleton of sharks and the preservation of stomach contents are rarely observed in the fossil record. Here we report on a partial skeleton of a lamniform shark, including portions of the visceral arches and the anterior segment of the vertebral column, collected from the late Miocene beds of the Pisco Formation exposed at Cerro Yesera (Ica Desert, South Peru). Based on the morphology of the preserved teeth, this specimen was determined as a juvenile of the extinct lamnid species Cosmopolitodus hastalis. The shark skeleton includes remains of fish (featuring a pilchard determined as Sardinops sp. cf. S. sagax) in the abdominal region. These fish remains are interpreted herein as the fossilized stomach contents of the shark. For the first time, piscivory is demonstrated in a juvenile individual of Cosmopolitodus hastalis. This result is consistent with the current knowledge about the feeding habits of immature individuals of extant lamniform shark species (including Carcharodon carcharias and Isurus oxyrinchus). Our report further outlines the fundamental role of schooling pilchards in the late Miocene trophic chains of the highly productive coastal waters off present South Peru. Moreover, the find of this well preserved shark skeleton strengthens the qualification of the Pisco Formation as a Fossil-Lagerstätte, and emphasizes the role of early mineralization processes in cases of exceptional preservation

Evaluación del cultivo de sorgo (Sorghum bicolor (L.) Moench) cv. ABS-4600 establecido en dos sistemas de siembra bajo diferentes tipos de fertilización fertilización. EL Plantel, postrera 2019

El estudio se llevó a cabo en la unidad experimental “EL PLANTEL” propiedad de la Universidad Nacional Agraria (UNA) se encuentra entre los 12° 06 ́ 24 ́ ́ – 12° 06 ́ 30 ́ ́ Latitud Norte y entre los 86° 04 ́ 46 ́ ́ – 86° 05 ́ 27 ́ ́ Longitud Oeste, con el propósito de evaluar el cultivo de sorgo [Sorghum bicolor (L.) Moench] cv. ABS-4600 sembrado como cultivo puro y en asocio con frijol Mungo [Vigna radiata (L.) R. Wilczek] bajo fertilización química, orgánica y combinada. Se estableció un experimento bifactorial con un diseño de Bloques Completos al Azar (BCA) de cuatro repeticiones y cuatro tratamientos, en los cuales los tratamientos se distribuyeron de la siguiente forma para los dos diferentes factores (tipos de siembra) sorgo como cultivo puro, sorgo con frijol mungo en un sistema de asocio y (tipo de fertilización), el T1 (cp) Biogreen, T2 (A) Biogreen, T3 (cp) químico, T4 (A) químico, T5 (cp) biogreen + químico, T6 (A) Biogreen + químico, T7 (cp) cero aplicaciones, T8 (A) cero aplicaciones. Las variables en ambos factores fuerón sometidas a un análisis de varianza, por medio de la prueba de Tukey. Se utilizó el programa estadístico INFOSTAT. La fertilización se realizó en base al establecimiento de los tratamientos aplicando químico (12-30-10) a razón de 130 kg ha-1 y 65 kg ha-1 de urea, biogreen a razón de 6 363.62 kg ha-1, en la combinación de biogreen + químico la relación fue de y 75 kg ha-1 y 3 181.82 kg ha-1respectivamente y hay cero aplicaciones para el testigo absoluto. Las variables que no dieron significancia estadística fueron altura de la planta, número de hojas, densidad poblacional, número de granos por panoja, peso de 1 000 granos, rendimiento del grano, biomasa seca y el porcentaje de materia seca. Para las concentraciones de nutrientes solo en elemento calcio no se encontró diferencia significativa, en comparación a los otros elementos que presentan diferencia, como en las extracciones de nitrógeno, fósforo, potasio, magnesio, manganeso, hierro, zinc, en las cuales la mayor extracción que hubo fue en la de potasio con 36.27 kg ha

Correlato entre el diagnóstico clínico, laparoscópico y por biopsia de los pacientes con ascitis

Objetivo: Se trató de estudiar la utilidad de la laparoscopia en la evaluación de la ascitis. Material y métodos: Estudio descriptivo, transversal y retrospectivo realizado en el Hospital Nacional Arzobispo Loayza de Lima. Se revisaron historias clínicas de 39 pacientes con ascitis hospitalizados en los servicios de Medicina desde septiembre de 1998 a diciembre de 2002 y de enero de 2005 a marzo de 2007. La laparoscopia y biopsia peritoneal fueron realizadas en el servicio de Gastroenterología. Se hizo la correlación entre los diagnósticos cl´ínico, laparoscópico y de biopsia de las tres condiciones más frecuentes: neoplasia intraabdominal, tuberculosis peritoneal y hepatopatía crónica. Resultados: Fueron 30 mujeres (76,92%) y 9 varones (23,08%). El promedio de edad fue de 50,75 años. La correlación entre el diagnóstico clínico y la biopsia y entre el diagnóstico laparoscópico y la biopsia fue de: 33% y 88% para tuberculosis, 40% y 93,3% para neoplasia intraabdominal y 33% y 87,5% para hepatopatía crónica. Hubo complicaciones durante la laparoscopia en el 9,21% de los pacientes. Conclusiones: La causa más frecuente de ascitis fue la neoplasia intraabdominal. Hubo alta correlación entre los diagnósticos laparoscópicos con respecto a la biopsia para las tres entidades, en especial para neoplasia intraabdominal.&nbsp